Pros
Flexibility is the main upside of this role. Depending on the shift, the work could be pretty stimulating (e.g. different environments/events), and it was often quite social.
Cons
Despite the company putting you on a 0-hour contract, they nevertheless call you and badger you to work more shifts as if you were a full-time worker (at least in my experience). The emphasis on presentation at times felt mildly discriminatory - being conventionally good-looking is clearly something they look for, especially when it comes to bartending and more senior roles. The work can also be physically tiring, and if the shift was particularly busy or understaffed, we sometimes wouldn't be given a break. Ultimately, the pay is also not great, although probably typical for similar roles at different companies.